JPH05246389A - Exhaust emission control device for outboard motor - Google Patents

Abstract

PURPOSE:To obtain specified exhaust emission purifying effect by disposing a catalyst of sufficient capacity in the case of leading a first exhaust passage from an engine to an exhaust air expansion chamber below the engine. CONSTITUTION:An engine 10 is disposed at the upper part of the casing of an outboard motor 1 fitted to a hull 2, and an exhaust air expansion chamber 29 is provided in a position below the engine 10. A first exhaust passage A for communicating the engine 10 with the exhaust air expansion chamber 29 is provided being opened into the exhaust air expansion chamber 29. A second exhaust passage B for communicating the exhaust air expansion chamber 29 with an underwater exhaust outlet 39 is further provided, and a catalyst 35 is disposed in the second exhaust passage B or the exhaust air expansion chamber 29, between the opening position of the first exhaust passage A and the lower end of the engine 10. The first exhaust passage A from the engine 10 is led to the approximately center part of the exhaust air expansion chamber 29 below the engine 10, and the catalyst 35 is disposed on either side of the first exhaust passage A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus for an outboard motor mounted on a hull, and more particularly to an exhaust gas purifying apparatus for an outboard motor having a catalyst in an exhaust system.

[0002]

2. Description of the Related Art An outboard motor mounted on a hull is equipped with an engine, and it is desirable to take measures against exhaust gas in this outboard motor to prevent air pollution. Therefore, for example, as disclosed in Japanese Patent Laid-Open No. 55-10043, a catalyst is provided in the exhaust gas passage of the engine, and CO (carbon monoxide) or HC (hydrocarbon) in the exhaust gas is generated by this catalyst.
There is something to reduce such.

By the way, in this exhaust gas purifying apparatus for an outboard motor, the catalyst is arranged in the exhaust passage connecting the engine and the exhaust expansion chamber in the casing, so that the exhaust passage of the engine is throttled at the catalyst. Therefore, although CO and HC in the exhaust gas can be reduced, the exhaust resistance increases and the engine performance deteriorates. Therefore, as disclosed in, for example, Japanese Unexamined Patent Publication No. 4-39195, the engine is arranged above the casing of the outboard motor attached to the hull, and the exhaust expansion chamber is provided in the casing. A first exhaust passage communicating with
Further, a second exhaust passage that connects the exhaust expansion chamber and the underwater exhaust outlet is provided, and a catalyst is arranged at a position above the water surface of the second exhaust passage when the ship is stopped to clean the exhaust gas by the catalyst and the engine. There are those that ensure improved performance.

[0004]

By the way, in this one, the space below the engine is divided into two spaces, a space in which the first exhaust passage is arranged and a space in which the catalyst is arranged. However, when the first exhaust passage from the engine is guided to the exhaust expansion chamber below the engine, it may be difficult to guide the first exhaust passage only to one portion of the peripheral portion below the engine.

In such a case, if the space under the engine is divided into two spaces, that is, a space for arranging the exhaust pipe and a space for arranging the catalyst as in the conventional case, a sufficient capacity of the catalyst is arranged. Therefore, there is a problem that a predetermined exhaust gas purification effect cannot be obtained.

The present invention has been made in view of the above point, and when the first exhaust passage from the engine is guided to the exhaust expansion chamber below the engine, a catalyst having a sufficient capacity is arranged to provide a predetermined exhaust gas purification effect. It is an object of the present invention to provide an exhaust gas purification device for an outboard motor that can obtain the above.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 arranges an engine in an upper part of a casing of an outboard motor attached to a hull, and in the casing at a lower position of the engine. An exhaust expansion chamber, a first exhaust passage communicating with the engine and the exhaust expansion chamber and opening in the exhaust expansion chamber, and a second exhaust passage communicating between the exhaust expansion chamber and the underwater exhaust outlet. In the exhaust gas purification device for an outboard motor, wherein a catalyst is disposed between the opening position of the first exhaust passage and the lower end of the engine in the second exhaust passage or the exhaust expansion chamber, the first exhaust gas from the engine. It is characterized in that the passage is guided to a substantially central portion of the exhaust expansion chamber below the engine, and the catalyst is arranged on both sides of the first exhaust passage.

According to a second aspect of the present invention, the engine is arranged above the casing of the outboard motor attached to the hull, and an exhaust expansion chamber is provided in the casing below the engine. A first exhaust passage communicating with the exhaust expansion chamber and opening in the exhaust expansion chamber is provided, and a second exhaust passage communicating between the exhaust expansion chamber and the underwater exhaust outlet is provided, and the second exhaust passage or the exhaust expansion is provided. In an exhaust gas purification apparatus for an outboard motor, wherein a catalyst is arranged indoors between an opening position of the first exhaust passage and a lower end of the engine, the at least two first exhaust passages are connected to the exhaust expansion chamber below the engine. The plurality of first exhaust passages are arranged in a plurality of peripheral portions of a space below the engine, and an intermediate portion sandwiched by the plurality of first exhaust passages arranged in the peripheral portion. Is characterized in that a said catalyst.

[0009]

According to the first aspect of the invention, the first engine
When the exhaust passage is guided to a substantially central portion of the exhaust expansion chamber below the engine, and catalysts are arranged on both sides of the first exhaust passage, and the first exhaust passage from the engine is guided to the exhaust expansion chamber below the engine. , Without greatly bending the first exhaust passage,
A sufficient amount of catalyst can be arranged, and a predetermined exhaust gas purification effect can be obtained.

According to the second aspect of the present invention, at least two first exhaust passages are guided to the exhaust expansion chamber below the engine, and the plurality of first exhaust passages are provided in a plurality of peripheral portions of the space below the engine. When the catalyst is arranged in an intermediate portion which is arranged and which is sandwiched by a plurality of first exhaust passages arranged in this peripheral portion, and when the first exhaust passage from the engine is guided to the exhaust expansion chamber below the engine, it is arranged below the engine. Even in the case where it is difficult to introduce the catalyst only in one place, it is possible to arrange a catalyst having a sufficient capacity and to obtain a predetermined exhaust gas purification effect without greatly bending the first exhaust passage.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an exhaust gas purifying apparatus for an outboard motor according to the present invention will be described below in detail with reference to the accompanying drawings.

First, an embodiment of an exhaust gas purifying apparatus for an outboard motor according to the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a side view of the outboard motor shown partially broken, FIG. 2 is a sectional view of an engine of the outboard motor, and FIG. 3 is a sectional view showing an exhaust system of the outboard motor.

As shown in FIG. 1, the outboard motor 1 includes a clamp bracket 3 attached to a hull 2, a swivel bracket 5 tiltably connected to the clamp bracket 3 via a tilt shaft 4, and a swivel bracket 5. And a propulsion unit 7 connected to the steering shaft 6 via the steering shaft 6. The propulsion unit 7 can be tilted up and down with the tilt shaft 4 as the center of rotation, and
The steering shaft 6 can be turned to the left and right around the turning center.

The propulsion unit 7 has an upper casing 8 and a lower casing 9, an engine 10 is arranged in the upper casing 8, a propeller 11 is arranged in the lower part of the lower casing 9, and the propeller 11 is The engine 10 is driven by the power transmitted from a power transmission mechanism (not shown). 9A is a lower casing when tilted up by the operation of a tilting device (not shown).

In this embodiment, the engine 10 is a V-type 6-cylinder two-cycle engine. A cylinder head 13 is attached to a cylinder block 12 of the engine 10 to form a V-type cylinder 14. A piston 15 is reciprocally provided in each of the cylinders 14, and the piston 15 is connected to a crankshaft 17 via a connecting rod 16. The crank shaft 17 is vertically supported by the cylinder block 12, and power is transmitted from the crank shaft 17 to the propeller 11 via a power transmission mechanism (not shown).

An intake pipe 18 is connected to the cylinder block 12 of the engine 10, and a reed valve 19 is provided in the intake pipe 18. A vaporizer 20 is attached to the intake pipe 18.
Is connected to the carburetor 20, and a silencer 21 is connected to the carburetor 20. A scavenging passage 22 is formed in the cylinder block 12 outside the cylinder 14, and the air-fuel mixture in the crank chamber 23 is supplied to the combustion chamber 24 through the scavenging passage 22. Exhaust ports 25 are formed inside the cylinders 14 facing each other, and the exhaust ports 25 are gathered on the same side.

A base plate 2 is provided below the engine 10.
6 is attached, a spacer plate 27 is attached to the base plate 26, and a partition wall 28 is connected to the lower side of the spacer plate 27.
An exhaust expansion chamber 29 is provided below the engine 10 by the valve 8.

At the center of the base plate 26, the engine 1
Exhaust passage 3 communicating with each exhaust collecting passage 30
1 is formed, an exhaust passage 32 communicating with the exhaust passage 31 is formed in the center of the spacer plate 27, and an exhaust pipe 33 is connected to the lower side of the spacer plate 27 so as to communicate with the exhaust passage 32. There is. In this way, the first exhaust passage A is constituted by 30, 31, 32 and 33. Each exhaust pipe 33 is located in the exhaust expansion chamber 29, and the opening 33a of the one exhaust pipe 33 projects into the exhaust expansion chamber 29 longer than the opening 33a of the other exhaust pipe 33. The lengths of the first exhaust passages A of the left and right banks are made substantially equal to derive sufficient engine performance.

As shown in FIGS. 1 and 3, the exhaust gas from the engine 10 is substantially centered in the exhaust expansion chamber 29 without being greatly bent by the first exhaust passage A extending downward from the center of the engine 10 as it is. The exhaust resistance is reduced to prevent the engine output from decreasing. The water surface L is when the ship is stopped.

Further, between the base plate 26 and the spacer plate 27, exhaust pipes 34 and 34b which are respectively in contact with the spacer plate 27 in the front and rear are provided at positions on the left and right sides of the exhaust passages 30 and 32, and between the exhaust pipes 34a and 34b. Each of the catalysts 35 arranged in the above is provided.

The exhaust pipes 34a on the left and right sides,
The catalyst 35 and the exhaust pipe 34b communicate the exhaust expansion chamber 29 and the exhaust passage 36 formed in the spacer plate 27, and the exhaust pipe 37 is connected to communicate with the exhaust passage 36. The exhaust pipe 37 is connected to the lower casing 9 Exhaust passage 38 formed in the
The exhaust passage 38 communicates with an underwater exhaust outlet 39 formed at the rear of the propeller 11, and a second exhaust passage B that connects the exhaust expansion chamber 29 and the underwater exhaust outlet 39 is provided with these. There is. Therefore, the exhaust gas guided to the exhaust expansion chamber 29 is branched by the exhaust pipe 34 and guided to the second exhaust passage B, and is discharged into the water from the underwater exhaust outlet 39 of the second exhaust passage B.

The catalyst 35 arranged in the second exhaust passage B
Are independently provided on both sides of the first exhaust passage A,
The respective catalysts 35 are arranged in the second exhaust passage B using a space formed between the opening position of the first exhaust passage A and the lower end of the engine 10. Although the catalyst 35 is arranged between the exhaust passage 34a and the exhaust passage 34b of the second exhaust passage B, the catalyst 35 is disposed in the exhaust expansion chamber 29 in the first exhaust passage A.
It may be arranged between the opening position of the engine and the lower end of the engine 10.

In this way, the first exhaust passage A from the engine 10 is guided to the exhaust expansion chamber 29 below the engine 10,
By arranging the catalysts 35 on both sides of the first exhaust passage A, even when the first exhaust passage A is guided from the center of the engine 10 to the exhaust expansion chamber 29 below the engine 10,
The catalyst 35 having a sufficient capacity can be arranged without greatly bending the exhaust passage A or breaking the outer shape line of the engine 10, and a predetermined exhaust gas purification effect can be obtained. Further, by thus disposing the catalyst 35 in a divided manner, the surface area becomes larger than that of the catalyst having the same volume, and the heat dissipation is improved.

Next, another embodiment of the exhaust gas purifying apparatus for an outboard motor according to the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 is a sectional view of the engine of the outboard motor, and FIG. 5 is a sectional view showing the exhaust system of the outboard motor.

This engine 10 has the same structure as that of the above-mentioned embodiment with the same reference numeral, and in this embodiment, a scavenging passage 50 is formed in the inner cylinder block 12 of each cylinder 14 facing each other. Exhaust ports 51 are formed outside the cylinder 14, and the exhaust ports 51 are gathered on the same side.

A base plate 52 is attached to the lower side of the engine 10, a spacer plate 53 is attached to the base plate 52, and a section for draining a drainage hole 54A is formed below the spacer plate 53. The wall 54 is connected, and the partition wall 54 provides an exhaust expansion chamber 55 below the engine 10.

The engine 1 is provided on both sides of the base plate 52.
Exhaust passage 5 communicating with each exhaust collecting passage 56 of 0
7 are formed, an exhaust passage 58 communicating with the exhaust passage 57 is formed on both sides of the spacer plate 53, and the exhaust passages 5 are formed below the spacer plate 53.
An exhaust pipe 59 is connected so as to communicate with 8. The respective exhaust pipes 59 are located on both sides in the exhaust expansion chamber 55, and the openings 59a of the exhaust pipe 59 are located at the water surface L1 due to the external water entering the exhaust expansion chamber 55 through the water drain hole 54A when the ship is stopped. It is in the opposite position. In this way, the engine 10 and the exhaust expansion chamber 55 are communicated with each other, and the exhaust expansion chamber 5
A first exhaust passage A opening in 5 is provided, and the engine 1
As shown in FIG. 5, the exhaust gas from 0 is exhausted in the exhaust expansion chamber 55.
Is discharged inside. The first exhaust passage A extends downward from both sides of the engine 10 as it is and is guided to both sides of the exhaust expansion chamber 55 without being greatly bent, so that the exhaust resistance is small and the output of the engine is not lowered.

Further, an exhaust pipe 60 is provided between the base plate 52 and the spacer plate 53 at a position between the exhaust passages 57 and 58, and the respective exhaust pipes 6 are provided.
0 is provided with a catalyst 61. Each of the exhaust pipes 60 communicates with the exhaust expansion chamber 55 and the exhaust passage 58A formed in the spacer plate 53, and further communicates with the exhaust pipe 62. The exhaust gas guided to the exhaust expansion chamber 55 is branched by the exhaust pipe 60, guided to the second exhaust passage B, and discharged from the second exhaust passage B into water.

12A, 52A and 52B are water jackets, respectively, and are provided with exhaust passages 56 and 57 and a catalyst 61.
Is cooled, flows out from the water drain hole 54A, and is discharged into water together with the exhaust gas. During high-speed operation, the ship is planing,
Since the water level L of the outside water is lowered, all the water in the exhaust expansion chamber 55 is exhausted from the drain hole 54A, and a sufficient expansion chamber volume is secured.

In this way, the two first exhaust passages A are guided to the exhaust expansion chamber 55 below the engine 10, and the plurality of first exhaust passages A are arranged in a plurality of peripheral portions of the space below the engine 10. The catalyst 61 is arranged in an intermediate portion sandwiched by the plurality of first exhaust passages A arranged in this peripheral portion.
Therefore, when the first exhaust passage A from the engine 10 is guided to the exhaust expansion chamber 55 below the engine 10, the engine 1
Even if it is difficult to guide the catalyst to only one place in the peripheral portion below 0, the catalyst 61 having a sufficient capacity can be obtained without greatly bending the first exhaust passage A or breaking the outline of the engine 10. Can be arranged, and a predetermined exhaust gas purification effect can be obtained.

Next, still another embodiment of the exhaust gas purifying apparatus for an outboard motor according to the present invention will be described with reference to FIGS. 6 and 7. FIG. 6 is a sectional view of the outboard motor, and FIG. 7 is a perspective view of the catalyst.

The casing 80 of the outboard motor 1 is provided with a bottom cowling 82 via an exhaust guide 81, and the bottom cowling 82 is provided with a top cowling 84 via a rubber seal 83. The top cowling 84 is made of resin, the engine 10 is disposed inside the top cowling 84, and a lower portion of the engine 10 is joined to a wall 81a of an exhaust guide 81, and the exhaust guide 81 and the engine 10 expand the exhaust gas. A chamber 85B is formed.

An exhaust pipe 86 connected to the center of the lower part of the engine 10 penetrates the exhaust guide 81, and an exhaust expansion chamber 85 formed by a partition wall 87 connected to the lower side of the exhaust guide 81.
The exhaust gas is guided to A, and the engine 10 and the exhaust expansion chamber 85A are communicated with each other by this.
A first exhaust passage A that opens in A is provided.

The exhaust expansion chamber 85A is communicated with the exhaust expansion chamber 85B through a passage 81b formed in the exhaust guide 81, and the exhaust expansion chamber 85B is formed integrally with the partition wall 87 through the passage 81c. It communicates with the passage 89.
The exhaust passage 89 constitutes a second exhaust passage B that connects the exhaust expansion chamber 85B and an underwater exhaust outlet (not shown).

A catalyst 90 shown in FIG. 7 is provided in the exhaust expansion chamber 85B.
The exhaust pipe 86 forming the first exhaust passage A is inserted into the hole 90a of the catalyst 90, whereby the catalyst 90 is arranged around the exhaust pipe 86.

In this way, the first exhaust passage A is extended downward from the engine 10 as it is, is guided to the substantially central portion of the exhaust expansion chamber 85A, and the catalyst 90 is provided around the first exhaust passage A.
Even when the first exhaust passage A from the center of the engine 10 is guided to the exhaust expansion chamber 85B below the engine 10, the first exhaust passage A is greatly bent or the outline line of the engine 10 is broken. In this way, the catalyst 90 having a sufficient capacity can be arranged, and a predetermined exhaust gas purification effect can be obtained.

Further, since the catalyst 90 is arranged in the exhaust expansion chamber 85B, excessive heating is prevented and durability is improved.

[0038]

As described above, the invention according to claim 1 is
Since the first exhaust passage from the engine is guided to a substantially central portion of the exhaust expansion chamber below the engine, and the catalysts are arranged on both sides of the first exhaust passage, the first exhaust passage from the center of the engine is located below the engine. Even when guided to the exhaust expansion chamber, the first
The catalyst having a sufficient capacity can be arranged without largely bending the exhaust passage or breaking the outline of the engine, and a predetermined exhaust gas purification effect can be obtained.

The invention according to claim 2 guides at least two first exhaust passages to an exhaust expansion chamber below the engine, and the plurality of first exhaust passages are provided in a plurality of peripheral portions of a space below the engine. Since the catalyst is arranged in the intermediate portion which is arranged and sandwiched by the plurality of first exhaust passages arranged in the peripheral portion, when the first exhaust passage from the engine is guided to the exhaust expansion chamber below the engine, Even when it is difficult to guide the gas to only one part of the peripheral part, a sufficient capacity of the catalyst can be arranged without greatly bending the first exhaust passage or breaking the outer shape line of the engine, and the predetermined exhaust gas A purification effect can be obtained.

[Brief description of drawings]

FIG. 1 is a side view showing a partially broken outboard motor.

FIG. 2 is a cross-sectional view of an engine of an outboard motor.

FIG. 3 is a cross-sectional view showing an exhaust system of an outboard motor.

FIG. 4 is a cross-sectional view of an engine of an outboard motor.

FIG. 5 is a cross-sectional view showing an exhaust system of the outboard motor.

FIG. 6 is a cross-sectional view of an outboard motor.

FIG. 7 is a perspective view of a catalyst.

[Explanation of symbols]

 1 Outboard Motor 2 Hull 10 Engine 29 Exhaust Expansion Chamber 39 Underwater Exhaust Outlet 35 Catalyst A First Exhaust Passage B Second Exhaust Passage

Claims (2)

[Claims] 1. An engine is arranged in an upper portion of a casing of an outboard motor attached to a hull, and an exhaust expansion chamber is provided below the engine, and the engine and the exhaust expansion chamber are communicated with each other in the exhaust expansion chamber. A first exhaust passage that opens is further provided, and a second exhaust passage that communicates the exhaust expansion chamber with an underwater exhaust outlet is provided, and the opening position of the first exhaust passage and the opening position of the first exhaust passage in the second exhaust passage or the exhaust expansion chamber. In an exhaust gas purifying apparatus for an outboard motor, in which a catalyst is arranged between lower ends of the engine, the first exhaust passage from the engine is guided to a substantially central portion of an exhaust expansion chamber below the engine, and the first exhaust passage An exhaust gas purifying apparatus for an outboard motor, wherein the catalyst is arranged on both sides. 2. An engine is arranged in an upper part of a casing of an outboard motor attached to a hull, and an exhaust expansion chamber is provided below the engine, and the engine and the exhaust expansion chamber are communicated with each other in the exhaust expansion chamber. A first exhaust passage that opens is further provided, and a second exhaust passage that communicates the exhaust expansion chamber with an underwater exhaust outlet is provided, and the opening position of the first exhaust passage and the opening position of the first exhaust passage in the second exhaust passage or the exhaust expansion chamber. An exhaust gas purifying apparatus for an outboard motor, wherein a catalyst is disposed between the lower ends of the engine, the at least two first exhaust passages are guided to the exhaust expansion chamber below the engine, and the plurality of first exhaust passages are connected to the engine. Of the outboard motor, characterized in that the catalyst is arranged in a plurality of peripheral portions of a space below the space, and the catalyst is arranged in an intermediate portion sandwiched by the plurality of first exhaust passages arranged in the peripheral portion. Exhaust gas purification device.